I think it is good, that in spite of the availability of all type of new components these days like PICs, Si570, Atmel chips and so on, there are still radio fans who use the old valve technology.
The receiver is a design with one tube (EF80) and was designed for receiving AM stations in the medium wave broadcast band. The circuit contains a surprise: The anode voltage applied is only 6 Volts DC. In spite of this low supply voltage the receiver is quite sensitive. Under normal circumstances at least 15 stations can be heard through the headphones.
Here some nice pictures including the circuit diagram:
MW radio with battery and headphones, design by PA2GHJ
Side view also showing Amroh 402 coil
Circuit diagram 1 valve receiver